CVE-2026-21916

HIGH

Junos OS: A low privileged user can escalate their privileges so that they can login as root

Title source: cna
STIX 2.1

Description

A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system. When after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root. This issue affects Junos OS: * all versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S3, * 24.4 versions before 24.4R2-S2, * 25.2 versions before 25.2R2. This issue does not affect versions 25.4R1 or later.

Scores

CVSS v3 7.3
EPSS 0.0001
EPSS Percentile 1.8%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact total

Details

CWE
CWE-61
Status published
Products (12)
juniper/junos 23.2 (11 CPE variants)
juniper/junos 23.4 (10 CPE variants)
juniper/junos 24.2 (7 CPE variants)
juniper/junos 24.4 (6 CPE variants)
juniper/junos 25.2 (4 CPE variants)
juniper/junos < 23.2
Juniper Networks/Junos OS < 23.2R2-S7
Juniper Networks/Junos OS 23.4 - 23.4R2-S6
Juniper Networks/Junos OS 24.2 - 24.2R2-S3
Juniper Networks/Junos OS 24.4 - 24.4R2-S2
... and 2 more
Published Apr 09, 2026
Tracked Since Apr 10, 2026